The dynamics of opinion expression

Research paper by Felix Gaisbauer, Eckehard Olbrich, Sven Banisch

Indexed on: 01 Jan '20Published on: 29 Dec '19Published in: arXiv - Physics - Physics and Society


We introduce a model of public opinion expression. Two groups of agents with different opinion on an issue interact with each other, changing the willingness to express their opinion according to whether they perceive themselves as part of the majority or minority opinion. We formulate the model as a multi-group majority game and investigate the Nash equilibria. We also provide a dynamical systems perspective: Using the reinforcement learning algorithm of Q-learning, we reduce the $N$-agent system in a mean-field approach to two dimensions which represent the two opinion groups. This two-dimensional system is analyzed in a comprehensive bifurcation analysis of its parameters. The model identifies structural conditions for public opinion predominance of different groups. We also show under which circumstances a minority can dominate public discourse. This offers direct connection to a central opinion expression theory of the social sciences, the spiral of silence.